Min-Chi Chiu

Center of pressure progression characteristics under the plantar region for elderly adults

This investigation identifies the center of pressure (COP) progression characteristics under the plantar region for elderly adults during barefoot walking. A total of 60 healthy adults (30 young and 30 old) were recruited. The young and elderly participants had average ages of 23.6 (SD=2.7) and 70.8 (SD=4.1) years old, respectively. All subjects had normal foot arch and no relevant musculoskeletal disease in the lower extremities. The foot pressure measurement system (RS-scan(®) system) was used to measure the center of pressure coordinates (COP), progression angle and COP velocity. Four sub-phases of the stance phase were calculated. The initial contact (ICP) and forefoot contact phase (FFCP) corresponded to the loading response. The foot flat phase (FFP) coincided with the mid-stance. The forefoot push-off phase (FFPOP) corresponded to the terminal stance and pre-swing phases. The analytical results revealed that age effects were found in the relative time percentages for the initial contact, foot flat and forefoot push-off phases during foot movement. The elderly subjects exhibited significant medial COP curve and faster COP velocity during the initial contact phase and more pronated mid-foot posture and slower COP velocity during the mid-stance. The older adults tended to have a more pronated foot and displayed a significant medial COP curve compared to young adults. These COP progression characteristics can provide further insight into relevant foot function and gait performance evaluations for older adults.

Gait speed and gender effects on center of pressure progression during normal walking

The COP progression is the trajectory of the center of foot pressure. Thirty healthy young adults were recruited to participate in this study. All subjects were asked to walk randomly at four different speeds (3km/h, preferred walking speed, 4km/h and 5km/h). A foot pressure measurement system (RS-scan(®) system) was used to collect the center of pressure (COP) coordinates, COP progression angle and the COP velocity. Four sub-phases of the stance phase were calculated. The initial contact (ICP) and forefoot contact phase (FFCP) corresponded to the loading response. The foot flat phase (FFP) coincided with the mid-stance. The forefoot push-off phase (FFPOP) corresponded to the terminal stance and pre-swing phases. The results of this study indicate that the percentage of time (% time) of COP progression on the ICP, FFCP, FFP and FFPOP were approximately 7.0%, 4.8%, 48.8% and 39.4%, respectively. The COP progression angle was 4.1 (SD=1.6)° with an inward curve and the average COP velocity was 31.6cm/s (SD=5.3). The walking speed influenced the % time in the FFP and FFPOP. As the walking speed increased, the % time of COP progression decreased in mid-stance and increased in the terminal and pre-swing stances. Moreover, gender affected the COP progression angle. Men had a significantly larger deviating angle than women during FFCP, FFP and FFPOP. The COP characteristics can offer useful information for clinical rehabilitation in foot functional and structural evaluation.

Smart technologies for assisting the life quality of persons in a mobile environment: a review

Extant methods for quality-of-life enhancement cannot be applied to assist people in mobile environments. For overcoming this problem, this paper investigates how smart technologies can be applied to enhance the life quality of a person in a mobile environment. First, a number of smart technology applications were analyzed, from which the smart technologies suitable for improving a specific life quality were found out. To a person in a mobile environment, awareness, comfort, efficiency, immediacy, mobility, preparedness, and responsiveness were considered as more important types of the life quality. To improve these, the most effective smart technologies were concluded as smart mobile services, smart phone, smart glasses/spectacles/contact lens, and smart surveillance camera. The contribution of this study includes a systematic procedure for applying smart technologies to improving the life quality of a mobile person, and a novel method that involves applying the Kano quality model to quantify life quality from several innovative viewpoints. The results provided useful guides for making plans to improve the life quality of persons in a mobile environment.

The relationship between handlebar and saddle heights on cycling comfort

This study aims to clarify the relationship between handlebar and saddle heights on cycling comforts by assessing the kinematics, kinetics, physiological loading and subjective perceived exertion rating. Twenty young adults with mean age 24.6 years (SD=0.1) were recruited to participate in this study. A commercial city bike with the adjustable handlebar and saddle had been set on the indoor cycling stands. All subjects were asked to ride randomly with 9 different postures (3 handle ×3 saddle heights) for continuous one hour. A 3-D motion analysis system (Zebris Medical GmbH, Germany) was used to collect the kinematic data. The body pressure measurement system (Body Pressure Measurement System, Tekscan, U.S.A) was applied to measure the pressure distribution, force and displacement of centre of mass (COM). A heart rate monitor (Polar RS-800, Kempele, Finland) was used to record the heart rate as the physiological loading. Moreover, a subjective perceived exertion rating scale (Borg CR-10) was used to assess subjective comfort around the body regions. The results of this study indicated that the lower handlebar with higher saddle cause greater ROM in wrist-ulnar deviation, wrist extension, trunk flexion and hip abduction. It also reveals more force on hand region, more discomfort around hand, ankle and back, and higher physiological loading. While cycling with higher handlebar and lower saddle, it has more ROM in wrist flexion, more body displacement on buttock region, little trunk forward, and more discomfort rating in buttock region. For handlebar and saddle adjustment, the considerations of body dimensions and characteristics, the relationship between handlebar and saddle heights might improve the cycling comfort and diminish musculoskeletal injury.

Visual fatigue occurrence time when using hand-held intelligent devices

Because the mobile phone becomes cheaper and cheaper, the Smartphone will be popular in our life in recent years. Smartphone display technologies have two types, including TFT-LCD (thin film transistor-liquid crystal display) and AMOLED (active matrix organic light-emitting diode). Little studies investigated time to visual fatigue for watching these two display types. Therefore, this study expects to find time to fatigue while using these two display types in order to prevent users from accumulative visual fatigue after prolonged viewing the small size screens. This study recruited 19 young volunteers, 10 males and 9 females, for the experiment. TFT-LCD and AOMLED of display panels were used for test. Another independent variable was the visual stimulation scenarios, including static and dynamic stimulation scenarios. The static stimulation scenario was to read a novel about swordsman on a mobile phone screen. The dynamic stimulation scenario was to play “Jewel Block” on a mobile phone. Objective eyestrain occurrence time and the subjective maximum time to fatigue were measured here for prolonged viewing the mobile phone screen. The results indicated that the time to fatigue from TFT-LCD was significantly longer than that of AMOLED. Dynamic stimulation scenario caused significantly longer time to fatigue than static one. The findings of this study are very useful to develop an ambient intelligent system being able to monitor the time spent for watching from the screen and to intelligently remind the user to take a break at the right time.

Evaluation of Four Eyestrain Recovery Methods for Visual Display Terminal Workers

The purpose of this research was to compare four eyestrain recovery methods, and then to find out the best way to eliminate eye fatigue from watching the electronic text. Four visual fatigue recovery methods included a short rest, eye drops, eye massager A (Vibratory), and eye massager B (Pneumatic). We recruited 20 young adults for the experiment. Their ages are between 19 to 25 years. Each participant performed four different experimental trials in four different days. Two visual fatigue indicators were collected before the experiment, i.e., high frequency component (HFC) of accommodative micro-fluctuation waveform and subjective rating (SR) of visual fatigue. The participants performed searching operation firstly, and then, one of the four recovery methods was tested. Experimental results show that the visual fatigue recovery method had a significantly effect on the HFC. The eye massager A had a significantly better effect than the eye drops and a short rest.

Usability evaluation of the universal computer workstation under supine, sitting and standing postures

The purpose of this study was to evaluate the usability of the self-made universal computer workstation. The 9 handicapped and 10 healthy adults were recruited to participate in this study, in order to understand the performances of computer operation, ratings in comfort and satisfaction for using the tested workstation in different positions. This workstation can be successfully adjusted for standing, sitting, and supine postures. This workstation also allows easy access of wheelchair. No significant differences in performances were found among supine, sitting, and standing postures. All of the participants considered this workstation comfortable. Most handicapped participants preferred to adopt supine posture to use the computer. The experimental results revealed that supine posture lead to more comfort in the lower back without decreasing performances while using a computer. Further, the healthy participants had the mean rating in satisfaction of 3.7, which was similar to that of the handicapped. It indicates that the tested workstation satisfied both the handicapped and the healthy participants. The findings of this study can provide helpful information for further improvement of a universal computer workstation.